Month 1 https://gladiator.tf/sales?item=Midnight%20Whirlwind%20Taunt:%20Fresh%20Brewed%20Victory&at=2022-05-30T21:30:14.374Z

1 @ 3 keys 28 ref

1 @ 3 keys 31.33 ref

1 @ 3 keys 31.55 ref

1 @ 3 keys 31.88 ref

1 @ 3 keys 32.44 ref

1 @ 3 keys 34.66 ref

2 @ 3 keys 50.88 ref

2 @ 4 keys

1 @ 4 keys 14.66 ref

Month 2 https://gladiator.tf/sales?item=Midnight%20Whirlwind%20Taunt:%20Fresh%20Brewed%20Victory&at=2022-04-30T21:30:14.374Z

1 @ 3 keys 28 ref

Month 3 https://gladiator.tf/sales?item=Midnight%20Whirlwind%20Taunt:%20Fresh%20Brewed%20Victory&at=2022-03-30T21:30:14.374Z

1 @ 3 keys 32.33 ref

1 @ 3 keys 33.33 ref

1 @ 3 keys 34.22 ref

https://marketplace.tf/items/tf2/1113;5;u3008

https://mannco.store/item/440-midnight-whirlwind-unusual-taunt-fresh-brewed-victory

Outdated

https://backpack.tf/item/2776356886

https://gladiator.tf/listings/625e197ad8f6a20148a204c0

~3.6 keys

https://backpack.tf/item/8800787536

https://gladiator.tf/listings/6256244302d993aac0552b16

~3.45 keys

Classies: https://gladiator.tf/time-machine?item=Midnight%20Whirlwind%20Taunt:%20Fresh%20Brewed%20Victory&at=2022-05-30T21:31:18.615Z

~3.5 key buyers

There are quite a few ~3.45 key sales, but only two at ~3.4. I'll compromise and take 3.45 - 4.2 keys here.